Subclinical Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A Meta-Analysis

Prediction model for leaflet thrombosis in patients undergoing transcatheter aortic valve implantation: the EFFORT study

BACKGROUND

Leaflet thrombosis (LT) is a multifaceted and underexplored condition that can manifest following transcatheter aortic valve implantation (TAVI). The objective of this study was to formulate a prediction model based on laboratory assessments and clinical parameters, providing additional guidance and insight into this relatively unexplored aspect of post-TAVI complications.

METHODS

The present study was an observational prospective hypothesis-generating study, including 101 patients who underwent TAVI and a screening for LT (the primary endpoint) by multidetector computed tomography (MDCT). All images were acquired on a third-generation dual-source CT system. Levels of von Willebrand factor (vWF) activity, hemoglobin (Hb), and lactate dehydrogenase (LDH) were measured among other parameters. A predictive score utilizing binary logistic regression, Kaplan-Meier time-to-event analysis, and receiver operating characteristics (ROC) analysis was established.

RESULTS

LT (11 subclinical and 2 clinical) was detected in 13 of 101 patients (13%) after a median time to screening by MDCT of 105 days (IQR, 98-129 days). Elevated levels of vWF activity (> 188%) pre-TAVI, decreased Hb values (< 11.9 g/dL), as well as increased levels of LDH (> 312 U/L) post-TAVI and absence of oral anticoagulation (OAC) were found in patients with subsequent LT formation as compared to patients without LT. The established EFFORT score ranged from - 1 to 3 points, with an increased probability for LT development in patients with ≥ 2 points (85.7% of LT cases) vs < 2 points (14.3% of LT cases; p < 0.001). Achieving an EFFORT score of ≥ 2 points was found to be significantly associated with a 10.8 times higher likelihood of developing an LT (p = 0.001). The EFFORT score has an excellent c-statistic (area under the curve (AUC) = 0.89; 95% CI 0.74-1.00; p = 0.001) and a high negative predictive value (98%).

CONCLUSION

An EFFORT score might be a helpful tool to predict LT development and could be used in risk assessment, if validated in confirmatory studies. Therefore, the score has the potential to guide the stratification of individuals for the planning of subsequent MDCT screenings.

Durability of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is now utilised as a less invasive alternative to surgical aortic valve replacement (SAVR) across the whole spectrum of surgical risk. Long-term durability of the bioprosthetic valves has become a key goal of TAVI as this procedure is now considered for younger and lower-risk populations. The purpose of this article is to present a state-of-the-art overview on the definition, aetiology, risk factors, mechanisms, diagnosis, clinical impact, and management of bioprosthetic valve dysfunction (BVD) and failure (BVF) following TAVI with a comparative perspective versus SAVR. Structural valve deterioration (SVD) is the main factor limiting the durability of the bioprosthetic valves used for TAVI or SAVR, but non-structural BVD, such as prosthesis-patient mismatch and paravalvular regurgitation, as well as valve thrombosis or endocarditis may also lead to BVF. The incidence of BVF related to SVD or other causes is low (<5%) at midterm (5- to 8-year) follow-up and compares favourably with that of SAVR. The long-term follow-up data of randomised trials conducted with the first generations of transcatheter heart valves also suggest similar valve durability in TAVI versus SAVR at 10 years, but these trials suffer from major survivorship bias, and the long-term durability of TAVI will need to be confirmed by the analysis of the low-risk TAVI versus SAVR trials at 10 years.

Severe aortic stenosis treated with transcatheter aortic valve implantation or surgical aortic valve replacement with Perimount in Western Denmark 2016-2022: a nationwide retrospective study

OBJECTIVES

The healthcare registries in Denmark present a unique opportunity to gain novel insights into the outcomes associated with both transcatheter and surgical approaches to aortic valve replacement. Our objective is to enhance shared decision-making by comparing long-term mortality and clinical outcomes between treatments.

METHODS

This observational study included all patients with severe aortic stenosis undergoing elective isolated transfemoral transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) in Western Denmark between January 2016 and April 2022. Patient population and clinical data were identified from the Western Danish Heart Registry and the National Danish Patient Registry, respectively. A propensity score-matched population was generated. Outcomes were investigated according to Valve Academic Research Consortium-3.

RESULTS

A total of 2269 TAVI patients and 1094 SAVR patients where identified. The propensity score-matched population consisted of 468 TAVI patients (mean[SD]age, 75.0[5.3] years) and 468 SAVR patients (mean[SD] age, 75.1[4.6]years). The Kaplan-Meier estimate for the 5-year all-cause mortality was 29.8% in the TAVI group and 16.9% for in the SAVR group (P = 0.019). The risk of all stroke or transient ischaemic attack after five year was 15.1% in the TAVI group and 11.0% in the SAVR group (P = 0.047).

CONCLUSIONS

This study underscores the importance of evaluating all patient factors when choosing an aortic valve replacement method. Surgical aortic valve replacement was an excellent choice, especially for patients with New York Heart Association class I/II, ≥75 age, left ventricular ejection fraction ≥50%, or longer life expectancy.

Bioprosthetic Aortic Valve Thrombosis: Definitions, Clinical Impact, and Management: A State-of-the-Art Review

Bioprosthetic aortic valve thrombosis is frequently detected after transcatheter and surgical aortic valve replacement due to advances in cardiac computed tomography angiography technology and standardized surveillance protocols in low-surgical-risk transcatheter aortic valve replacement trials. However, evidence is limited concerning whether subclinical leaflet thrombosis leads to clinical adverse events or premature structural valve deterioration. Furthermore, there may be net harm in the form of bleeding from aggressive antithrombotic treatment in patients with subclinical leaflet thrombosis. This review will discuss the incidence, mechanisms, diagnosis, and optimal management of bioprosthetic aortic valve thrombosis after transcatheter aortic valve replacement and bioprosthetic surgical aortic valve replacement.

Cerebrovascular events after transcatheter aortic valve implantation

Periprocedural stroke after transcatheter aortic valve implantation (TAVI) remains a significant issue, which is associated with high morbidity, and is increasingly important as intervention shifts to younger and lower-risk populations. Over the last decade of clinical experience with TAVI, the incidence of periprocedural stroke has stayed largely unchanged, although it is prone to underreporting due to variation in ascertainment methods. The aetiology of stroke in TAVI patients is multifactorial, and changing risk profiles, differing study populations, and frequent device iterations have made it difficult to discern consistent risk factors. The objective of this review is to analyse and clarify the contemporary published literature on the epidemiology and mechanisms of neurological events in TAVI patients and evaluate potential preventive measures. This summary aims to improve patient risk assessment and refine case selection for cerebral embolic protection devices, while also providing a foundation for designing future trials focused on stroke prevention.

Subclinical valve leaflet thrombosis following bioprosthetic aortic valve replacement

PURPOSE OF REVIEW

Subclinical leaflet thrombosis (SLT) is often an incidental finding characterized by a thin layer of thrombus involving one, two or three leaflets, with typical appearance on multi-detector computed tomography (MDCT) of hypo-attenuating defect at the aortic side of the leaflet, also called hypo-attenuating leaflet thickening (HALT). SLT may occur following both transcatheter aortic replacement (TAVR) or biological surgical aortic valve replacement (SAVR). The aim of this review is to present an overview of the current state of knowledge on the incidence, diagnosis, clinical impact, and management of SLT following TAVR or SAVR.

RECENT FINDINGS

SLT occurs in 10-20% of patients following TAVR and is somewhat more frequent than following SAVR (5-15%). SLT may regress spontaneously without treatment in about 50% of the cases but may also progress to clinically significant valve thrombosis in some cases. Oral anticoagulation with vitamin K antagonist is reasonable if SLT is detected by echocardiography and/or MDCT during follow-up and is generally efficient to reverse SLT. SLT is associated with mild increase in the risk of stroke but has no impact on survival. SLT has been linked with accelerated structural valve deterioration and may thus impact valve durability and long-term outcomes.

SUMMARY

SLT is often an incidental finding on echocardiography or MDCT that occurs in 10-20% of patients following TAVR or 5-15% following biological SAVR and is associated with a mild increase in the risk of thrombo-embolic event with no significant impact on mortality but may be associated with reduced valve durability.

Recent Advances in the Modification and Improvement of Bioprosthetic Heart Valves

Valvular heart disease (VHD) has become a burden and a growing public health problem in humans, causing significant morbidity and mortality worldwide. An increasing number of patients with severe VHD need to undergo heart valve replacement surgery, and artificial heart valves are in high demand. However, allogeneic valves from donors are lacking and cannot meet clinical practice needs. A mechanical heart valve can activate the coagulation pathway after contact with blood after implantation in the cardiovascular system, leading to thrombosis. Therefore, bioprosthetic heart valves (BHVs) are still a promising way to solve this problem. However, there are still challenges in the use of BHVs. For example, their longevity is still unsatisfactory due to the defects, such as thrombosis, structural valve degeneration, calcification, insufficient re-endothelialization, and the inflammatory response. Therefore, strategies and methods are needed to effectively improve the biocompatibility and longevity of BHVs. This review describes the recent research advances in BHVs and strategies to improve their biocompatibility and longevity.

Insights into calcific aortic valve stenosis: a comprehensive overview of the disease and advancing treatment strategies

Aortic valve stenosis is a disease characterized by thickening and narrowing of the aortic valve (AV), most commonly due to calcification, which leads to left ventricular outflow obstruction called calcific aortic valve disease (CAVD). CAVD presents as a progressive clinical syndrome with cardiorespiratory symptoms, often with rapid deterioration. The modern-day pathophysiology of CAVD involves a complex interplay of genetic factors, chronic inflammation, lipid deposition, and valve calcification, with early CAVD stages resembling atherosclerosis. Various imaging modalities have been used to evaluate CAVD, with a recent trend of using advanced imaging to measure numerous AV parameters, such as peak jet velocity. Significant improvements in mortality have been achieved with transcatheter AV repair, but numerous therapeutics and modalities are being researched to delay the progression of CAVD. This article aims to provide a comprehensive review of CAVD, explore recent developments, and provide insights into future treatments with various novel modalities.

Deformation in transcatheter heart valves: Clinical implications and considerations

Transcatheter aortic valve replacement (TAVR) has emerged as a preferred treatment modality for aortic stenosis, marking a significant advancement in cardiac interventions. Transcatheter heart valves (THVs) have also received approval for treating failed bioprosthetic valves and rings across aortic, mitral, tricuspid, and pulmonic positions. Unlike surgically implanted valves, which are sewn into the annulus, THVs are anchored through relative oversizing. Although THVs are designed to function optimally in a fully expanded state, they exhibit a certain degree of tolerance to underexpansion. However, significant deformation beyond this tolerance can adversely affect the valve's hemodynamics and durability, ultimately impacting patient outcomes. Such post-implantation deviations from the valve's intended three-dimensional design are influenced by a variety of physiological and anatomical factors unique to each patient and procedure, leading to underexpansion, eccentric expansion, and vertical deformation. These deformation patterns increase leaflet stress and strain, potentially causing fatigue and damage. This review article delves into the extent of THV deformation, its impact on leaflet function, hypoattenuating leaflet thickening, and structural valve degeneration. It provides an in-depth analysis of deformation specifics in different procedural contexts, including TAVR in native aortic stenosis, aortic and mitral valve-in-valve procedures, and redo-TAVR. Additionally, the review discusses strategies to mitigate THV deformation during the procedure, offering insights into potential solutions to these challenges.

Long-term prosthetic-associated subclinical thrombotic events evaluation by cardiac CTA after transcatheter aortic valve implantation: incidence and outcomes

OBJECTIVE

To observe prosthetic-associated subclinical thrombotic events (PASTE) after transcatheter aortic valve implantation (TAVI) by cardiac CTA, and assess their impact on long-term patient outcomes.

MATERIALS

We prospectively and consecutively enrolled 188 patients with severe aortic stenosis treated with TAVI from February 2014 to April 2017. At 5 years, 61 of 141 survived patients who had completed annual follow-up CTA (≥ 5 years) were included. We analyzed PASTE by CTA, including hypoattenuated leaflet thickening (HALT), sinus filling defect (SFD), and prosthesis filling defect (PFD). The primary outcome was a major adverse cardiovascular composite outcome (MACCO) of stroke, cardiac re-hospitalization, and bioprosthetic valve dysfunction (BVD); the secondary outcomes were bioprosthetic hemodynamics deterioration (PGmean) and cardiac dysfunction (LVEF).

RESULTS

During a median follow-up time of 5.25 years, long-term incidence of HALT, SFD, and PFD were 54.1%, 37.7%, and 73.8%, respectively. In the primary outcome, SFD and early SFD were associated with the MACCO (SFD: p = 0.005; early SFD: p = 0.018), and SFD was a predictor of MACCO (HR: 2.870; 95% CI: 1.010 to 8.154, p = 0.048). In the secondary outcomes, HALT was associated with increased PGmean (p = 0.031), while persistent HALT was correlated with ΔPGmean (β = 0.38, p = 0.035). SFD was negatively correlated with ΔLVEF (β = -0.39, p = 0.041), and early SFD was negatively correlated with LVEF and ΔLVEF (LVEF: r = -0.50, p = 0.041; ΔLVEF: r = -0.53, p = 0.030).

CONCLUSIONS

PASTE were associated with adverse long-term outcomes, bioprosthetic hemodynamics deterioration, and cardiac dysfunction. In particular, SFD was a predictor of MACCO and may be a potential target for anticoagulation after TAVI (NCT02803294).

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov ; Unique identifier: NCT02803294.

CRITICAL RELEVANCE STATEMENT

PASTE, especially SFD, after TAVI based on cardiac CTA findings impacts the long-term outcomes of patients which is a predictor of long-term major adverse outcomes in patients and may be a potential target for anticoagulation after TAVI.

KEY POINTS

Transcatheter aortic valve implantation is being used more often; associated subclinical thromboses have not been thoroughly evaluated. Prosthetic-associated subclinical thrombotic events were associated with adverse outcomes, bioprosthetic hemodynamics deterioration, and cardiac dysfunction. Studies should be directed at these topics to determine if they should be intervened upon.

Low- or standard-dose edoxaban versus antiplatelet therapy for leaflet thrombus and cerebral thromboembolism after TAVR: A prespecified analysis of randomized ADAPT-TAVR trial

BACKGROUND

The risks of leaflet thrombosis and the associated cerebral thromboembolism are unknown according to different anticoagulation dosing after transcatheter aortic valve replacement (TAVR). The aim was to evaluate the incidence of leaflet thrombosis and cerebral thromboembolism between low-dose (30 mg) or standard-dose (60 mg) edoxaban and dual antiplatelet therapy (DAPT) after TAVR.

METHODS

In this prespecified subgroup analysis of the ADAPT-TAVR trial, the primary endpoint was the incidence of leaflet thrombosis on 4-dimensional computed tomography at 6-months. Key secondary endpoints were new cerebral lesions on brain magnetic resonance imaging and neurological and neurocognitive dysfunction.

RESULTS

Of 229 patients enrolled in this study, 118 patients were DAPT group and 111 were edoxaban group (43 [39.1%] 60 mg vs 68 [61.3%] 30 mg). There was a significantly lower incidence of leaflet thrombosis in the standard-dose edoxaban group than in the DAPT group (2.4% vs 18.3%; odds ratio [OR] 0.11; 95% confidence interval [CI], 0.01-0.55; P = .03). However, no significant difference was observed between low-dose edoxaban and DAPT (15.0% vs 18.3%; OR 0.79; 95% CI, 0.32-1.81; P = .58). Irrespective of different antithrombotic regiments, the percentages of patients with new cerebral lesions on brain MRI and worsening neurological or neurocognitive function were not significantly different.

CONCLUSIONS

In patients without an indication for anticoagulation after TAVR, the incidence of leaflet thrombosis was significantly lower with standard-dose edoxaban but not with low-dose edoxaban, as compared with DAPT. However, this differential effect of edoxaban on leaflet thrombosis was not associated with a reduction of new cerebral thromboembolism and neurological dysfunction.

About different localization of hypoattenuated lesions following transcatheter aortic valve replacement

BACKGROUND

Subclinical leaflet thrombosis is diagnosed using multidetector computed tomography (MDCT) and is characterised by a meniscal-shaped hypoattenuated lesion of one or more leaflets. Transcatheter aortic self-expandable valves are commonly manufactured with pliable pericardium over a nitinol frame that forms leaflet and extra-leaflet components such as the valve skirt. Little is known about extra-leaflet hypoattenuated lesion localisation, including that at the anatomical sinus level. Thus, the main aim of this study was to describe leaflet and extra-leaflet (anatomic sinus and subvalvular level) hypoattenuated lesions following transcatheter aortic valve replacement with a self-expandable prosthesis. As a secondary aim, we sought to investigate predictors of hypoattenuated lesions.

METHODS

Fifty patients underwent MDCT at the follow-up.

RESULTS

At a follow-up of 12 months, hypoattenuated leaflet lesions with mild to severe restricted movement were detected in eight individuals (16%), anatomic sinus lesions were identified in nine patients (18%), with higher prevalence in the non-coronary sinus (16%), and subvalvular lesions with variable extension toward the valve inflow were diagnosed in eight patients (16%). In 4 patients (8%) the anatomic sinus thrombus was 'in overlap' with leaflet thrombus; in 3 patients (6%) was in continuity with subvalvular frame thrombus. Bicuspid valve was the only independent predictor associated with hypoattenuated lesions (adj OR 8.25 (95% CI: 1.38, 49.21), p = 0.02)).

CONCLUSIONS

This study demonstrated that hypoattenuated lesions could be identified not only at the leaflet but also at the subvalvular and anatomic sinus levels. The clinical relevance of such lesions remains unclear.

What is the current optimal antithrombotic therapy after transcatheter aortic valve implantation? Current evidence from Japan and the world

Aortic stenosis (AS) is a major valvular disease that can have a negative impact on patients' prognosis, and its prevalence is increasing due to an aging population worldwide. Transcatheter aortic valve implantation (TAVI) is a well-established therapy for symptomatic severe AS utilized across the entire surgical risk spectrum. Based on the recently published evidence of large, randomized controlled trials (RCTs), the number of patients undergoing TAVI is increasing worldwide. Ischemic and bleeding events are common after TAVI and can have serious consequences both immediately after the procedure and in the long-term. Antiplatelet therapy has been traditionally recommended to prevent thromboembolic events after TAVI. The situation regarding the optimal antithrombotic regimen following TAVI is rapidly changing because many game-changing RCTs have been published. This report provides an overview of the current status and remaining issues in the field of optimal antithrombotic therapy following TAVI, including its possible effect on leaflet thrombosis.

Evaluation of the anatomic sinus after transcatheter aortic valve replacement

BACKGROUND

Following transcatheter aortic valve replacement (TAVI), the newly formed 'anatomic sinus'. may contribute to the formation of subclinical leaflet thrombosis (SLT).The evaluation of root geometry after TAVI is generally performed using multi-detector computed tomography (MDCT), and the role of transthoracic echocardiography (2D TTE) requires further validation. Thus, we aimed to test the reproducibility of 2D TTE assessment of the anatomic sinus with MDCT as a reference and its association with SLT.

METHODS

2D TTE was performed in 90 patients, and the echocardiograms were analyzed offline. Both sinus of Valsalva (SOV) and prosthesis diameters were assessed in the long- and short-axis parasternal views (PLAX/PSAX), and the anatomic sinus area was calculated. Inter- and intra-observer reproducibility were assessed using the interclass correlation coefficient (ICC). MDCT was performed in 50 individuals to evaluate concordance with 2D TTE and to detect SLT.

RESULTS

There was excellent correlation regarding the diameter of the SOV and the prosthesis in PLAX (ICC: 0.93 (95% CI: 0.76,0.97); ICC: 0.80 (95% CI: 0.63,0.96)) and PSAX view (ICC: 0.90 (95% CI: 0.68,0.97); ICC: 0.88 (95% CI: 0.63,0.96)). Bland-Altman analysis of 2D TTE and MDCT anatomic sinus areas indicated a high level of agreement. SLT was detected in 8 individuals (16%); 3 patients had severe SLT at the level of 1 cusp.

CONCLUSIONS

2D TTE might play a role in the evaluation of the anatomic sinus after TAVI. The importance of this space and its effects on the SLT remain uncertain.

Antithrombotic Treatment After Transcatheter Valve Interventions: Current Status and Future Directions

PURPOSE

The optimal antithrombotic strategy after transcatheter valve interventions is a subject of ongoing debate. Although there is evidence from randomized trials in patients undergoing transcatheter aortic valve replacement (TAVR), current evidence on optimal antithrombotic management after transcatheter mitral or tricuspid valve interventions is sparse. This article appraises the current evidence on this topic.

METHODS

This narrative review presents key research findings and guideline recommendations, as well as highlights areas for future research.

FINDINGS

After TAVR, randomized trial evidence suggests that single antiplatelet therapy is reasonable for patients without pre-existing indications for oral anticoagulation (OAC). If there is a concurrent indication for OAC, the addition of antiplatelet therapy increases bleeding risk. Whether direct oral anticoagulants achieve better outcomes than vitamin K antagonists is uncertain in this setting. Although OAC has been shown to reduce subclinical leaflet thrombosis (which may progress to structural valve degeneration), bleeding events are unacceptably high. There is a lack of randomized trial data comparing antithrombotic strategies after transcatheter mitral or tricuspid valve replacement or after mitral or tricuspid transcatheter edge-to-edge repair. Single antiplatelet therapy after mitral or tricuspid transcatheter edge-to-edge repair may be appropriate, whereas at least 3 months of OAC is suggested after transcatheter mitral valve replacement or transcatheter tricuspid valve replacement.

IMPLICATIONS

Randomized studies are warranted to address the knowledge gaps in antithrombotic therapy after transcatheter valve interventions and to optimize outcomes.

Self-expanding and balloon-expandable valves in low risk TAVR patients

BACKGROUND

Recent randomized studies have broadened the indication of transcatheter aortic valve replacement (TAVR) to also include low-surgical-risk patients. However, the data on self-expanding (SE) and balloon-expandable (BE) valves in low-risk patients remain sparse.

METHODS

The current study is a post hoc analysis of combined data from both LRT 1.0 and 2.0 trials comparing BE and SE transcatheter heart valves.

RESULTS

A total of 294 patients received a BE valve, and 102 patients received an SE valve. The 30-day clinical outcomes were similar across both groups except for stroke (4.9% vs. 0.7%, p = 0.014) and permanent pacemaker implantation (17.8% vs. 5.8%, p < 0.001), which were higher in the SE cohort than the BE cohort. No difference was observed in terms of paravalvular leak (≥moderate) between the groups (0% vs. 1.5%, p = 0.577). SE patients had higher aortic valve area (1.92 ± 0.43 mm2 vs. 1.69 ± 0.45 mm2, p < 0.001) and lower mean gradient (8.93 ± 3.53 mmHg vs. 13.41 ± 4.73 mmHg, p < 0.001) than BE patients. In addition, the rate of subclinical leaflet thrombosis was significantly lower in SE patients (5.6% vs. 13.8%, p = 0.038).

CONCLUSION

In this non-randomized study assessing SE and BE valves in low-risk TAVR patients, SE valves are associated with better hemodynamics and lesser leaflet thrombosis, with increased rates of stroke and permanent pacemaker implantation at 30 days; however, this could be due to certain patient-dependent factors not fully evaluated in this study. The long-term implications of these outcomes on structural valve durability remain to be further investigated.

CLINICAL TRIAL REGISTRY

LRT 1.0: NCT02628899 LRT 2.0: NCT03557242.

Outcomes and performance of the ACURATE neo2 transcatheter heart valve in clinical practice: one-yearresults of the ACURATE neo2 PMCF Study

BACKGROUND

Transcatheter aortic valve implantation is an effective treatment for patients with aortic stenosis; however, complications related to paravalvular leakage (PVL) persist, including increased risk of mortality, cardiovascular mortality, and rehospitalisation.

AIMS

We sought to evaluate the clinical outcomes and valve performance at 1 year in patients with severe aortic stenosis treated with the ACURATE neo2 valve in a post-market clinical setting.

METHODS

Valve Academic Research Consortium-2 safety events were assessed up to 1 year. Independent core laboratories evaluated echocardiographic measures of valve performance and hypoattenuated leaflet thickening (HALT; as measured by four-dimensional computed tomography).

RESULTS

The study enrolled 250 patients (64% female; mean age: 81 years; baseline Society of Thoracic Surgeons risk score: 2.9±2.0%); 246 patients were implanted with ACURATE neo2. All-cause mortality was 0.8% at 30 days and 5.1% at 1 year. The 1-year rates for stroke and disabling stroke were 3.0% and 1.3%, respectively. Overall, HALT of >50% leaflet involvement of at least one leaflet was present in 9% of patients at 30 days and in 12% of patients at 1 year. No association was observed between the presence of HALT and 1-year clinical or haemodynamic outcomes. Early haemodynamic improvements were maintained up to 1 year (mean aortic valve gradient: 47.6±14.5 mmHg at baseline, 7.6±3.2 mmHg at 1 year; mean aortic valve area: 0.7±0.2 cm2 at baseline, 1.7±0.4 cm2 at 1 year). At 1 year, 99% of patients had mild or no/trace PVL (<1% had moderate PVL; no patient had severe PVL).

CONCLUSIONS

The study outcomes confirm favourable performance and safety up to 1 year in patients treated with ACURATE neo2 in routine clinical practice. (ClinicalTrials.gov: NCT04655248).

Frequency, Predictors, and Clinical Impact of Valvular and Perivalvular Thrombus After Transcatheter Aortic Valve Replacement

BACKGROUND

Subclinical aortic valve complex (valvular and perivalvular) thrombus is not rare after transcatheter aortic valve replacement (TAVR). The risk factors and clinical implications of these findings remain uncertain.

OBJECTIVES

This study sought to evaluate the frequency, predictors, and clinical outcome of aortic valve complex thrombus after TAVR.

METHODS

In the ADAPT-TAVR (Anticoagulation Versus Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization After Transcatheter Aortic Valve Replacement) trial comparing edoxaban vs dual antiplatelet therapy in TAVR patients without an indication for chronic anticoagulation, the frequency of valvular (subclinical leaflet thrombus) and perivalvular (supravalvular, subvalvular, and sinus of Valsalva) thrombus was evaluated by 4-dimensional computed tomography at 6 months. The association of these phenomena with new cerebral thromboembolism on brain magnetic resonance imaging, neurologic and neurocognitive dysfunction, and clinical outcomes was assessed.

RESULTS

Among 211 patients with 6-month computed tomography evaluations, 91 patients (43.1%) had thrombus at any aortic valve complex, 30 (14.2%) patients had leaflet thrombus, and 78 (37.0%) patients had perivalvular thrombus. A small maximum diameter of the stent at the valve level and low body surface area were independent predictors of aortic valve complex and perivalvular thrombus, and decreased renal function was an independent predictor of leaflet thrombus. No significant differences were observed in new cerebral lesions, neurologic or neurocognitive functions, or clinical outcomes among patients with or without valvular or perivalvular thrombus.

CONCLUSIONS

Subclinical aortic valve complex (valvular and perivalvular) thrombus was common in patients who had undergone successful TAVR. However, these imaging phenomena were not associated with new cerebral thromboembolism, neurologic or neurocognitive dysfunction, or adverse clinical outcomes. (Anticoagulation Versus Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization After Transcatheter Aortic Valve Replacement [ADAPT-TAVR]; NCT03284827).

Impact of leaflet thrombosis on valve haemodynamic status after transcatheter aortic valve replacement

OBJECTIVES

The effect of subclinical leaflet thrombosis, characterised by hypoattenuated leaflet thickening (HALT), on the valve haemodynamic function and durability of the bioprosthetic valve, is not yet determined. We determined the impact of HALT on valve haemodynamics after transcatheter aortic valve replacement (TAVR) and the predictors of haemodynamic structural valve deterioration (SVD).

METHODS

The Anticoagulation vs Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization after Transcatheter Aortic Valve Replacement(ADAPT-TAVR) trial is a multicenter, randomised trial that compared edoxaban and dual antiplatelet therapy in patients who had undergone successful TAVR. The presence of HALT was evaluated by four-dimensional CT at 6 months and serial echocardiography performed at baseline, immediately post-TAVR and after 6 months. SVD was defined as at least one of the following: (1) mean transprosthetic gradient ≥20 mm Hg, (2) change in the mean gradient ≥10 mm Hg from baseline, or (3) new or increase in intraprosthetic aortic regurgitation of at least ≥1 grade, resulting in moderate or greater regurgitation.

RESULTS

At 6 months, HALT was found in 30 of 211 (14.2%) patients. The presence of HALT did not significantly affect aortic valve mean gradients (with vs without HALT; 14.0±4.8 mm Hg vs 13.7±5.5 mm Hg; p=0.74) at 6 months. SVD was reported in 30 of 206 patients (14.6%) at 6-month follow-up echocardiography. Older age (OR: 1.138; 95% CI: 1.019 to 1.293; p=0.033), use of aortic valve size ≤23 mm (OR: 6.254; 95% CI: 2.230 to 20.569; p=0.001) and mean post-TAVR pressure gradient (OR: 1.233; 95% CI: 1.123 to 1.371; p<0.001) were independent predictors of haemodynamic SVD; however, the presence of HALT was not identified as a predictor of SVD.

CONCLUSIONS

In patients who had undergone successful TAVR, aortic valve haemodynamic status was not influenced by the presence of HALT. Although HALT was not a predictor of haemodynamic SVD at 6 months, it warrants further longer-term follow-up to evaluate the effect on long-term valve durability.

TRIAL REGISTRATION NUMBER

NCT03284827 (https://www.

CLINICALTRIALS

gov).

Bioprosthetic leaflet thrombosis and reduced leaflet motion after transcatheter aortic valve replacement: A systematic review and meta-analysis

BACKGROUND

Leaflet thrombosis and reduced leaflet motion have become a concern with the expanding use of transcatheter aortic valve replacement in lower-risk patients.

AIMS

To assess the proportions, predictors and clinical impact of leaflet thrombosis and reduced leaflet motion after transcatheter aortic valve replacement.

METHODS

We performed a meta-analysis of studies assessing the proportions of and/or clinical outcomes according to the presence of leaflet thrombosis after transcatheter aortic valve replacement identified with computed tomography and/or echocardiography.

RESULTS

Fifty-three studies, representing 25,258 patients undergoing transcatheter aortic valve replacement, were considered. The proportion of leaflet thrombosis was 5.2% overall, and was higher in computed tomography versus echocardiography (16.4% vs. 1.1%, respectively); reduced leaflet motion was identified in 11% of patients with four-dimensional computed tomography. Intra-annular bioprostheses were associated with a higher proportion of leaflet thrombosis, whereas chronic oral anticoagulation was protective for leaflet thrombosis in both computed tomography and echocardiographic studies (9.7% vs. 17.5%; relative risk [RR]: 0.51, 95% confidence interval [95% CI]: 0.37-0.71 and 0.9% vs. 2.7%; RR: 0.22, 95% CI: 0.06-0.79, respectively) and for reduced leaflet motion (2.5% vs. 12.4%; RR: 0.32, 95% CI: 0.13-0.76). Leaflet thrombosis was not associated with an increased risk of death, but with a higher risk of stroke in computed tomography studies (2.8% vs. 2.4%; RR: 1.63, 95% CI: 1.05-2.55), a difference more pronounced when considering reduced leaflet motion (3.5% vs. 1.7%; RR: 2.39, 95% CI: 0.63-8.34).

CONCLUSIONS

The proportion of leaflet thrombosis is highly variable according to the screening approach, the type of valve and the use of oral anticoagulation. The occurrence of cerebral events is increased when leaflet thrombosis and/or reduced leaflet motion are diagnosed, but leaflet thrombosis has no impact on survival.

Early 6 months usage of single anTiplAtelet OR anTicoAgulant followed by single antiplatelet after transcatheter aortic valve replacement: protocol for a multicentre, open-label, randomised controlled clinical trial

INTRODUCTION

The strategy for initiating antithrombotic therapy to prevent bioprosthetic valve thrombosis (BPVT) after transcatheter aortic valve replacement (TAVR) remains uncertain. There is still lacking evidence on the efficacy and safety of early 6 months usage of single-antiplatelet therapy (SAPT) or oral anticoagulant (OAC) after TAVR in patients without anticoagulant indications.

METHODS AND ANALYSIS

This is a multicentre, randomised controlled, open-label trial, and 650 patients undergoing TAVR from 13 top TAVR centres in China will be recruited. Each eligible participant will be randomly assigned to two groups (1:1 ratio) as (1) SAPT (aspirin 75-100 mg for 6 months) group or (2) OAC group (warfarin, therapeutic international normalised ratio at 1.8-2.5 for 6 months), both followed by sequential aspirin 75-100 mg for 6 months. Participants in both groups will be invited for three follow-up visits of 1, 6 and 12 months after discharge. We will use both the net clinical benefit endpoint (composite of all-cause mortality, myocardial infarction, stroke/transient ischaemic attacks, peripheral artery thrombosis, intracardiac thrombosis and major bleeding and disabling or life-threatening bleeding) and the BPVT endpoint evaluated by four-dimensional CT as our primary endpoints. P value of <0.05 of two-sided test will be considered statistically significant.

ETHICS AND DISSEMINATION

The present study was approved by the Institutional Review Boards at Fuwai Hospital, National Center for Cardiovascular Diseases of China (Approval No. 2023-1947). All patients will be informed of the details of the study and will sign an informed consent prior to inclusion in the study. Results of this study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05375474.

Self-Expandable Prosthesis Valve Adaptation: Non-Uniform Expansion and Stent Frame Decoupling

The incidence of non-uniform expansion in the context of the self-expandable transcatheter heart valve (THV) is little investigated, along with stent-frame decoupling, which is a form of stent adaptation, in which the lower part of the THV stent conforms to both the ellipticity of the left ventricle outflow tract and the native annulus while maintaining the higher part of the valve more circular. We analyzed post-implant multi-detector computed tomography scans in 50 patients. Prosthesis non-uniform expansion was assessed by computing the prosthesis eccentricity on 6 prespecified levels: (1) frame inflow, (2) native annulus, (3) leaflet inflow, (4) prosthesis waist, (5) leaflet outflow, and (6) frame outflow. Stent-frame decoupling was assessed by comparing the mean eccentricity on 6 different prosthesis levels. Implantation depth, leaflet expansion and alignment, and residual anatomic sinus area ratios were also calculated. Subclinical leaflet thrombosis was defined as hypoattenuated lesion of a meniscal shape. At a 12-month follow-up, non-uniform expansion was consistently detected at each valvular level. Highest eccentricity was measured at the native annulus level (eccentricity: 0.54 ±  0.12), while the lowest index at the frame outflow level (0.23 ± 0.11). Similar results were observed in the subgroup analyses of sizes 23, 26, 29, and 34. Eccentricity significantly decreased from the annulus level to the prosthesis frame outflow (p <0.001). Notably, the incidence of mild-to-severe subclinical leaflet thrombosis was relevant (16%). In conclusion, prosthesis non-uniform expansion and stent frame decoupling frequently occur after self-expandable THV replacement. The clinical and hemodynamic implications remain uncertain.

An investigator-sponsored pragmatic randomized controlled trial of AntiCoagulation vs AcetylSalicylic Acid after Transcatheter Aortic Valve Implantation: Rationale and design of ACASA-TAVI

BACKGROUND

The optimal antithrombotic therapy after transcatheter aortic valve implantation (TAVI) is unknown. Bioprosthetic valve dysfunction (BVD) is associated with adverse outcomes and may be prevented by anticoagulation therapy. A dedicated randomized trial comparing monotherapy NOAC to single antiplatelet therapy has not been performed previously. We hypothesize that therapy with any anti-factor Xa NOAC will reduce BVD compared to antiplatelet therapy, without compromising safety.

METHODS

ACASA-TAVI is a multicenter, prospective, randomized, open-label, blinded endpoint, all-comers trial comparing a monotherapy anti-factor Xa NOAC strategy (intervention arm) with a single antiplatelet therapy strategy (control arm) after successful TAVI. Three-hundred and sixty patients without indication for oral anticoagulation will be randomized in a 1:1 ratio to either apixaban 5 mg twice per day, edoxaban 60 mg daily, or rivaroxaban 20 mg daily for 12 months followed by acetylsalicylic acid 75 mg daily indefinitely, or to acetylsalicylic acid 75 mg daily indefinitely. The 2 co-primary outcomes are (1) incidence of Hypo-Attenuated Leaflet Thickening (HALT) on 4-dimensional cardiac CT at 12 months, and (2) a Safety Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction and stroke), and death from any cause, at 12 months.

RESULTS

The first 100 patients had a mean age of 74 ± 3.6 years, 33% were female, the average body-mass index was 27.9 ± 4.4 kg/m2, and 15% were smokers. A balloon-expanded valve was used in 82% and a self-expandable valve in 18%.

CONCLUSIONS

The trial is planned, initiated, funded, and conducted without industry involvement.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT05035277.

Leaflet thrombosis in transcatheter aortic valve intervention: mechanisms, prevention, and treatment options

Introduction

Transcatheter aortic valve intervention (TAVR) has emerged as a promising alternative to surgical aortic valve replacement for patients with severe aortic stenosis. However, leaflet thrombosis has raised concerns about the long-term durability and outcomes of TAVR. This study aims to provide an overview of the mechanisms, prevention strategies, and treatment options for leaflet thrombosis in TAVR.

Clinical evidence

Leaflet thrombosis refers to the formation of blood clots on bioprosthetic valve leaflets, leading to impaired leaflet mobility, early valve degeneration and dysfunction, and potential clinical implications. While the mechanisms underlying thrombus formation on valve leaflets are not fully understood, several factors, such as altered blood flow patterns within valve neosinuses, prothrombotic surfaces, and patient-related causes, have been implicated. Two distinct entities have been identified, namely, hypoattenuated leaflet thickening and restricted leaflet motion. Their occurrence appears dynamic over time and is related to the valve type. Imaging, including transesophageal echocardiography and multidetector computed tomography, plays a crucial role in the diagnosis and follow-up of leaflet thrombosis.

Prevention and treatment options

Preventing leaflet thrombosis requires a comprehensive and tailored approach involving identifying high-risk patients, close monitoring, and antithrombotic therapy. Antithrombotic therapy with dual antiplatelet agents or anticoagulation is commonly employed in TAVR patients, although the optimal regimen is yet to be defined. Novel antithrombotic agents, such as direct oral anticoagulants, are being investigated for their efficacy and safety in preventing leaflet thrombosis. When leaflet thrombosis is detected, treatment options include intensified antithrombotic therapy, valve-in-valve intervention, or balloon valvuloplasty. The long-term outcomes and impact of leaflet thrombosis on valve durability and patient prognosis are areas of ongoing research.

Summary

Leaflet thrombosis in TAVR is a considerable complication affecting valve function and patient outcomes. Understanding the mechanisms underlying thrombus formation and implementing appropriate prevention strategies are essential for mitigating this risk. Treatment options aim to restore leaflet mobility and optimize valve performance. Further research is needed to establish standardized protocols for antithrombotic therapy, identify high-risk patient populations, and determine the long-term consequences of leaflet thrombosis on TAVR outcomes.

Antithrombotic therapy with Transcatheter aortic valve replacement

Aortic valve replacement is a necessary management strategy for patients with severe aortic stenosis. The use of transaortic valve replacement (TAVR) has increased significantly over the last decade and now exceeds traditional surgical aortic valve replacement. Since the valve systems used in TAVR consist of bioprosthetic valve tissue encased in a metal stent frame, antithrombotic therapy recommendations cannot be extrapolated from prior data with differently constructed surgical bioprosthetic or mechanical valves. Data on the use of antithrombotic therapy with TAVR are a rapidly developing area of medicine. Choice of agents depends on several patient factors. Patients undergoing TAVR also have a relatively high incidence of subclinical valve thrombosis. The clinical impact of this phenomenon and the implications for antithrombotic therapy continue to evolve. It is critical for clinicians who treat patients undergoing TAVR to have a firm understanding of practice guidelines, the evolving evidence, and its implications for the use of antithrombotic therapy in these patients.

Antithrombotic therapy following transcatheter aortic valve intervention

Transcatheter aortic valve replacement (TAVR) is increasingly being performed to treat symptomatic patients with aortic stenosis and annual procedure volume has overtaken surgical aortic valve replacement in the United States. However, current international guidelines were written prior to the publication of several important recent studies. Furthermore, European and American guidelines differ in their recommendations of antithrombotic therapy following TAVR. Consequently, there is a need to examine the literature to provide clinicians guidance on the optimum antithrombotic strategy, particularly as different patient populations exist. In this review, we examine the data for antiplatelet and anticoagulation therapy post-TAVR.

Subclinical Leaflet Thrombosis Following Surgical and Transcatheter Aortic Valve Replacement: A Meta-Analysis

Subclinical leaflets valve thrombosis (SLT) is a recently identified phenomenon with multidetector computer tomography after tissue aortic valve replacement. Whether SLT is more frequent after transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) is currently not known. Thus, the aim of this pairwise meta-analysis was to investigate the incidence of SLT after both TAVR and SAVR, the association with anticoagulation therapy, and the risk for neurological events. We searched PubMed, Google Scholar, and Ovid MEDLINE/Embase (January 02, 2023, last update) (PROSPERO registration: CRD42022383295). Statistical analysis was performed according to a prespecified statistical analysis plan. Time-to-event outcomes were summarized as incidence rate ratios (IRR). Pooled estimates were calculated using inverse variance method and random effect model. Overall, 2 registries, 2 randomized trials, and 1 observational study (1,593 patients) were included in this meta-analysis. There was a statistically significant difference in the incidence rate at follow-up of SLT between patients who underwent TAVR and SAVR (IRR 2.07, 95% confidence interval [CI]: [1.06; 4.03], I2 79%, 95% CI: [44; 92], p = 0.03). Oral anticoagulation therapy was associated with a reduced incidence of SLT (IRR 7.51, 95% CI: [3.24; 17.37], I2 62%, 95% CI: [0; 87], p <0.001). However, the incidence of later neurological events did not differ between patients with or without SLT (IRR 1.05, 95% CI: [0.32; 3.47], p = 0.93). In conclusion, SLT was more frequently detected after TAVR than SAVR. However, it was not associated with an increased risk for neurological events. Oral anticoagulation therapy seemed to reduce the incidence of SLT.

Effect of Edoxaban Versus Antiplatelet Therapy on Leaflet Thrombosis and Cerebral Thromboembolism After TAVI According to Major Clinical and Anatomic Factors in Prespecified Subgroup Analysis from the ADAPT-TAVR Trial

It is unknown whether edoxaban versus dual antiplatelet therapy (DAPT) has differential treatment effects on leaflet thrombosis, cerebral thromboembolism, and neurologic or neurocognitive dysfunction according to clinical and anatomic factors after transcatheter aortic valve implantation. To investigate the relative effects of edoxaban and DAPT on leaflet and cerebral thromboembolism in patients with major risk factors. The primary end point of this study was the incidence of leaflet thrombosis on computed tomography at 6 months. The secondary end points were new cerebral lesions on brain magnetic resonance imaging and neurologic and neurocognitive dysfunction between baseline and 6-month follow-up. Cox regression models assessed the consistency of the treatment effects in the prespecified subgroups. The favorable effect of edoxaban versus DAPT on the leaflet thrombosis was consistent across multiple clinical or anatomic subgroups, without significant interaction between the drug effect and each subgroup (p for interaction for age = 0.597, gender = 0.557, body mass index = 0.866, Society of Thoracic Surgeons score = 0.307, valve type = 0.702, edoxaban reduction criteria = 0.604, and valve morphology = 0.688). However, the incidence of new cerebral lesions on brain magnetic resonance imaging and worsening of neurologic and neurocognitive function were not significantly different between the groups among the various key subgroups. The relative effects of edoxaban and DAPT on the risk of leaflet thrombosis, cerebral thromboembolism, and neurologic dysfunction were consistent across a diverse spectrum of clinical or anatomical factors. Further studies are required to define tailored antithrombotic therapy for high-risk groups with specific clinical or anatomic characteristics.

Early Detection of Risk of Neo-Sinus Blood Stasis Post-Transcatheter Aortic Valve Replacement Using Personalized Hemodynamic Analysis

Background

Despite the demonstrated benefits of transcatheter aortic valve replacement (TAVR), subclinical leaflet thrombosis and hypoattenuated leaflet thickening are commonly seen as initial indications of decreased valve durability and augmented risk of transient ischemic attack.

Methods

We developed a multiscale patient-specific computational framework to quantify metrics of global circulatory function, metrics of global cardiac function, and local cardiac fluid dynamics of the aortic root and coronary arteries.

Results

Based on our findings, TAVR might be associated with a high risk of blood stagnation in the neo-sinus region due to the lack of sufficient blood flow washout during the diastole phase (e.g., maximum blood stasis volume increased by 13, 8, and 2.7 fold in the left coronary cusp, right coronary cusp, and noncoronary cusp, respectively [N = 26]). Moreover, in some patients, TAVR might not be associated with left ventricle load relief (e.g., left ventricle load reduced only by 1.2 % [N = 26]) and diastolic coronary flow improvement (e.g., maximum coronary flow reduced by 4.94%, 15.05%, and 23.59% in the left anterior descending, left circumflex coronary artery, and right coronary artery, respectively, [N = 26]).

Conclusions

The transvalvular pressure gradient amelioration after TAVR might not translate into adequate sinus blood washout, optimal coronary flow, and reduced cardiac stress. Noninvasive personalized computational modeling can facilitate the determination of the most effective revascularization strategy pre-TAVR and monitor leaflet thrombosis and coronary plaque progression post-TAVR.

Comparison of oral anticoagulation by vitamin-K antagonists and non-vitamin-K antagonists for treatment of leaflet thickening after transcatheter aortic valve implantation (TAVI)

INTRODUCTION

Hypoattenuated leaflet thickening (HALT), as identified by CT imaging, is not infrequent after transcatheter aortic valve implantation (TAVI). The best choice of oral anticoagulation is unknown. We compared the effectiveness of Direct Oral AntiCoagulants (DOAC) and Vitamin-K Antagonists (VKA) to resolve HALT in patients with serial CT aquisitions.

METHODS

A total of 46 consecutive TAVI patients in whom anticoagulation had been initiated because of HALT and who underwent follow-up CT were identified. Indication and type of anticoagulation was according to physician discretion. Patients on DOAC were compared to VKA therapy regarding resolution of HALT.

RESULTS

Mean age of the 46 patients was 80 ± 6 years (59% men), and the mean duration of anticoagulation was 156 days. Overall, 41 patients (89%) showed resolution of HALT with anticoagulation therapy, whereas HALT persisted in 5 patients (11%). Resolution of HALT was seen in 26 out of 30 (87%) patients receiving VKA and in 15 out of 16 (94%) patients receiving DOAC, respectively. Groups did not differ regarding age, cardiovascular risk factors, TAVI prosthesis type and size or duration of anticoagulation (all p > 0.05).

CONCLUSION

Anticoagulation therapy resolves leaflet thickening after TAVI in most patients. Non-Vitamin-K antagonists seem to be an effective alternative to Vitamin-K antagonists. This finding needs to be confirmed in larger prospective trials.

Meta-Analysis Assessing Efficacy and Safety of Vitamin K Antagonists Versus Direct Oral Anticoagulants for Atrial Fibrillation After Transcatheter Aortic Valve Implantation

Patients who underwent transcatheter aortic valve implantation (TAVI) with concomitant atrial fibrillation (AF) are at a higher risk for thromboembolic and bleeding events. The optimal antithrombotic strategy for patients with AF after TAVI remains unclear. We sought to determine the comparative efficacy and safety of direct oral anticoagulants (DOAC) versus oral vitamin K antagonists (VKAs) in these patients. Electronic databases such as PubMed, Cochrane, and Embase databases were searched till January 31, 2023, for relevant studies evaluating clinical outcomes of VKA versus DOAC in patients with AF after TAVI. Outcomes assessed were (1) all-cause mortality, (2) stroke, (3) major/life-threatening bleeding, and (4) any bleeding. Hazard ratios (HRs) were pooled in meta-analysis using random effect model. Nine studies (2 randomized and 7 observational) were included in systematic review, and 8 studies with 25,769 patients were eligible to be included in the meta-analysis. The mean age of the patients was 82.1 years, and 48.3% were male. Pooled analysis using random-effects model showed no statistically significant difference in all-cause mortality (HR 0.91, 95% confidence interval [CI] 0.76 to 1.10, p = 0.33), stroke (HR 0.96, 95% CI 0.80 to 1.16, p = 0.70), and major/life-threatening bleeding (HR 1.05, 95% CI 0.82 to 1.35, p = 0.70) in patients that received DOAC compared with oral VKA. Risk of any bleeding was lower in the DOAC group compared with oral VKA (HR 0.83, 95% CI 0.76 to 0.91, p = 0.0001). In patients with AF, DOACs appear to be a safe alternative oral anticoagulation strategy to oral VKA after TAVI. Further randomized studies are required to confirm the role of DOACs in those patients.

Medium-Term Outcomes of the Different Antithrombotic Regimens After Transcatheter Aortic Valve Implantation

Bioprosthetic valve thrombosis is associated with accelerated bioprosthesis degeneration and valve re-replacement. Whether 3-month warfarin use after transcatheter aortic valve implantation (TAVI) protects against such consequences is unknown. We aimed to investigate if 3-month warfarin treatment after TAVI is associated with better outcomes than dual antiplatelet therapy (DAPT) and single antiplatelet therapy (SAPT) at medium-term follow-up. Adults who underwent TAVI were identified retrospectively (n = 1,501) and classified into warfarin, DAPT, and SAPT groups based on antithrombotic regimen received. Patients with atrial fibrillation were excluded. Outcomes and valve hemodynamics were compared between the groups. Annualized change from baseline in mean gradients and effective orifice area at last follow-up echocardiography was calculated. Overall, 844 patients were included (mean age: 80 ± 9 years, 43% women; 633 receiving warfarin, 164 DAPT, and 47 SAPT). Median time to follow-up was 2.5 (interquartile range 1.2 to 3.9) years. There were no differences in the adjusted outcome end points of ischemic stroke, death, valve re-replacement/intervention, structural valve degeneration, or their composite end point at follow-up. Annualized change in aortic valve area was significantly higher in DAPT (-0.11 [0.19] cm²/year) than warfarin (-0.06 [0.25] cm²/y, p = 0.03), but annualized change in mean gradients was not different (p >0.05). In conclusion, antithrombotic regimen, including warfarin, after TAVI was associated with marginally lower decrease in aortic valve area but no difference in medium-term clinical outcomes compared with DAPT and SAPT.

First Ex Vivo Animal Study of a Biological Heart Valve Prosthesis Sensorized with Intravalvular Impedance

IntraValvular Impedance (IVI) sensing is an innovative concept for monitoring heart valve prostheses after implant. We recently demonstrated IVI sensing feasible in vitro for biological heart valves (BHVs). In this study, for the first time, we investigate ex vivo the IVI sensing applied to a BHV when it is surrounded by biological tissue, similar to a real implant condition. A commercial model of BHV was sensorized with three miniaturized electrodes embedded in the commissures of the valve leaflets and connected to an external impedance measurement unit. To perform ex vivo animal tests, the sensorized BHV was implanted in the aortic position of an explanted porcine heart, which was connected to a cardiac BioSimulator platform. The IVI signal was recorded in different dynamic cardiac conditions reproduced with the BioSimulator, varying the cardiac cycle rate and the stroke volume. For each condition, the maximum percent variation in the IVI signal was evaluated and compared. The IVI signal was also processed to calculate its first derivative (dIVI/dt), which should reflect the rate of the valve leaflets opening/closing. The results demonstrated that the IVI signal is well detectable when the sensorized BHV is surrounded by biological tissue, maintaining the similar increasing/decreasing trend that was found during in vitro experiments. The signal can also be informative on the rate of valve opening/closing, as indicated by the changes in dIVI/dt in different dynamic cardiac conditions.

Contemporary issues and lifetime management in patients underwent transcatheter aortic valve replacement

Latest clinical trials have indicated favorable outcomes following transcatheter aortic valve replacement (TAVR) in low surgical risk patients with severe aortic stenosis. However, there are unanswered questions particularly in younger patients with longer life expectancy. While current evidence are limited to short duration of clinical follow-up, there are certain factors which may impair patients clinical outcomes and quality-of-life at long-term. Contemporary issues in the current TAVR era include prosthesis-patient mismatch, heart failure hospitalization, subclinical thrombosis, future coronary access, and valve durability. In this review, the authors review available evidence and discuss each remaining issues and theoretical treatment strategies in lifetime management of TAVR patients.

Computed tomography imaging for subclinical leaflet thrombosis following surgical and transcatheter aortic valve replacement

Subclinical leaflet thrombosis (LT) may occur following surgical and transcatheter aortic valve replacement. Computed tomography (CT) has become an established imaging modality to diagnose subclinical LT following bioprosthetic aortic valve replacement. Even so, there is a limited (but growing) experience in utilizing CT imaging for this indication. This review emphasizes a systematic approach to acquiring and analysing CT imaging for subclinical LT, highlighting evidence surrounding clinical sequelae of subclinical LT and anti-thrombotic implications following diagnosis.

Prosthesis Tailoring for Patients Undergoing Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has risen over the past 20 years as a safe and effective alternative to surgical aortic valve replacement for treatment of severe aortic stenosis, and is now a well-established and recommended treatment option in suitable patients irrespective of predicted risk of mortality after surgery. Studies of numerous devices, either newly developed or reiterations of previous prostheses, have been accruing. We hereby review TAVI devices, with a focus on commercially available options, and aim to present a guide for prosthesis tailoring according to patient-related anatomical and clinical factors that may favor particular designs.

Antithrombotic therapy after transcatheter aortic valve replacement

Aortic stenosis is a major valvular disease, which affects prognosis, and its prevalence is increasing due to an aging population. Transcatheter aortic valve replacement (TAVR) is a well-established therapy for symptomatic severe aortic stenosis across the entire risk spectrum, and the number of patients who undergo TAVR is increasing worldwide. Generally, ischemic and bleeding events after TAVR are not rare and can be devastating. Thus, antithrombotic therapy is recommended to prevent thromboembolic events after TAVR. Recently, a lot of randomized control trials have been published on antithrombotic therapy following TAVR, and the situation regarding the optimal antithrombotic regiment following TAVR is dramatically changing. This report reviews the current status and remaining issues in the field of optimal antithrombotic therapy following TAVR and leaflet thrombosis.

Direct oral anticoagulant versus antiplatelet therapy following transcatheter aortic valve replacement in patients without prior or concurrent indication for anticoagulation: A meta-analysis of randomized studies

INTRODUCTION

The antithrombotic management following transcatheter aortic valve replacement (TAVR) in patients who do not have a concurrent indication for long-term anticoagulation therapy is an ongoing source of debate.

METHODS

We performed a systematic review and meta-analysis to compare direct oral anticoagulants (DOACs) versus antiplatelet therapy after TAVR in patients without a concomitant indication for chronic oral anticoagulation. PubMed, Embase, and Cochrane databases were searched. Only randomized controlled trials were included. Risk ratios (RR) with p < 0.05 were considered statistically significant.

RESULTS

Three studies were included, with 2922 patients who underwent TAVR, of whom 1463 (50.1%) received DOACs. Patients who received DOACs therapy had significantly higher all-cause mortality (RR: 1.68; 95% confidence intervals [CI]: 1.22-2.30; p = 0.001) and non-cardiovascular mortality (RR: 2.33; 95% CI: 1.13-4.80; p = 0.02). The incidence of major bleeding was not significantly different between the groups (5.3% vs. 3.8%; RR: 1.44; 95% CI: 0.90-2.32; p = 0.13). There was no difference between DOACs and antiplatelet therapy in terms of: ischemic stroke (RR: 1.28; 95% CI: 0.76-2.15; p = 0.35) and cardiovascular mortality (RR: 1.36; 95% CI: 0.92-2.03; p = 0.13). Lastly, the DOACs group had a significantly lower risk of valve thrombosis than the antiplatelet group (0.8% vs. 3.2%; RR: 0.27; 95% CI: 0.14-0.51; p < 0.0001).

CONCLUSION

In this meta-analysis of randomized studies comparing DOACs to antiplatelet therapy after TAVR in patients without a concomitant indication for anticoagulation, DOACs were associated with a lower incidence of valve thrombosis and a higher rate of all-cause mortality, driven by an increase in noncardiac causes of death.

Natural History of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A 5-Year Follow-Up Study

Background Subclinical leaflet thrombosis, characterized by hypoattenuated leaflet thickening (HALT) on multidetector computed tomography, is common after transcatheter aortic valve replacement (TAVR). Because little is known about the long-term natural history of subclinical HALT, we aimed to investigate this in patients who underwent TAVR without using additional anticoagulation. Methods and Results We retrospectively evaluated patients who underwent TAVR with the Edwards SAPIEN-XT at our institute between October 2013 and December 2015. Patients were grouped according to the presence or absence of HALT within 1 year after TAVR (HALT and No-HALT groups). The primary outcome, defined as the composite of all-cause mortality, heart failure readmission, and ischemic stroke, was compared. Valve performance was assessed over time by transthoracic echocardiography. Among 124 patients (men: 29.1%; median age, 85 years), 27 (21.8%) showed HALT on multidetector computed tomography within 1 year after TAVR. No patient required additional anticoagulation for treating HALT because of the absence of valve-related symptomatic deterioration. During the median follow-up period of 4.7 years (interquartile range, 4.0-5.6), the rate of primary outcome and valve performance was not statistically different between the 2 groups (37.0% versus 38.1%; log-rank test P=0.92; mean pressure gradient, 9 mm Hg [8-14 mm Hg] versus 10 mm Hg [7-15 mm Hg]; P=0.51, respectively). Conclusions Approximately 20% of patients after TAVR had HALT within 1 year; however, that did not change the risk of subsequent adverse cardiovascular events or the valve performance with statistical significance for up to 5 years despite no additional anticoagulation therapy.

[How to select the best device using pre-TAVR CT scan]

Transcatheter aortic valve replacement or TAVR has become the gold standard for the treatment of symptomatic and severe aortic valve stenosis in elderly patients. Although the role of computed tomography imaging was initially limited to the determination of the optimal vascular approach, it has progressively matured to become the pilar of TAVR work-up while being standardized by consensus conferences. The list of evaluated elements includes aortic annulus diameter, the optimal projection curve, the number of aortic leaflets, the severity and localization of calcifications, coronary ostial height, membranous septum length and aortic angulation. The proper and cautious evaluation of these elements may help evaluating the risk for the main periprocedural complications such as coronary obstruction, annular rupture, permanent pacemaker implantation or procedural failure and selecting the optimal transcatheter heart valve and its size, according to the patient's specific anatomy. In this review, we detail how the evaluation of these parameters may impact the selection of the transcatheter heart valve.

The search for optimal antithrombotic therapy in transcatheter aortic valve implantation: facts and uncertainties

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure, which is used frequently in patients with symptomatic severe aortic valve stenosis. Most patients undergoing TAVI are over 80 years of age with a high bleeding as well as thrombotic risk. Despite the increasing safety of the procedure, thromboembolic events [stroke, (subclinical) valve thrombosis] remain prevalent. As a consequence, antithrombotic prophylaxis is routinely used and only recently new data on the efficacy and safety of antithrombotic drugs has become available. On the other hand, these antithrombotic drugs increase bleeding in a population with unique aortic stenosis-related bleeding characteristics (such as acquired von Willebrand factor defect and angiodysplasia). In this review, we discuss the impact of thromboembolic and bleeding events, the current optimal antithrombotic therapy based on registries and recent randomized controlled trials, as well as try to give a practical guide how to treat these high-risk patients. Finally, we discuss knowledge gaps and future research needed to fill these gaps.

Late Transcatheter Aortic Valve Thrombosis Leading to Cardiogenic Shock

A 67-year-old woman with prior transcatheter aortic valve replacement presented with worsening dyspnea. Imaging revealed transcatheter aortic valve thrombosis and aortic stenosis. Despite oral anticoagulation, she progressively deteriorated and developed cardiogenic shock. We highlight the Heart Team's role in treating this unusual late thrombosis. (Level of Difficulty: Intermediate.).

Hybrid heart valves with VEGF-loaded zwitterionic hydrogel coating for improved anti-calcification and re-endothelialization

With the aging of the population in worldwide, valvular heart disease has become one of the most prominent life-threatening diseases in human health, and heart valve replacement surgery is one of the therapeutic methods for valvular heart disease. Currently, commercial bioprosthetic heart valves (BHVs) for clinical application are prepared with xenograft heart valves or pericardium crosslinked by glutaraldehyde. Due to the residual cell toxicity from glutaraldehyde, heterologous antigens, and immune response, there are still some drawbacks related to the limited lifespan of bioprosthetic heart valves, such as thrombosis, calcification, degeneration, and defectiveness of re-endothelialization. Therefore, the problems of calcification, defectiveness of re-endothelialization, and poor biocompatibility from the use of bioprosthetic heart valve need to be solved. In this study, hydrogel hybrid heart valves with improved anti-calcification and re-endothelialization were prepared by taking decellularized porcine heart valves as scaffolds following grafting with double bonds. Then, the anti-biofouling zwitterionic monomers 2-methacryloyloxyethyl phosphorylcholine (MPC) and vascular endothelial growth factor (VEGF) were utilized to obtain a hydrogel-coated hybrid heart valve (PEGDA-MPC-DHVs@VEGF). The results showed that fewer platelets and thrombi were observed on the surface of the PEGDA-MPC-DHVs@VEGF. Additionally, the PEGDA-MPC-DHVs@VEGF exhibited excellent collagen stability, biocompatibility and re-endothelialization potential. Moreover, less calcification deposition and a lower immune response were observed in the PEGDA-MPC-DHVs@VEGF compared to the glutaraldehyde-crosslinked DHVs (Glu-DHVs) after subcutaneous implantation in rats for 30 days. These studies demonstrated that the strategy of zwitterionic hydrogels loaded with VEGF may be an effective approach to improving the biocompatibility, anti-calcification and re-endothelialization of bioprosthetic heart valves.

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A new and promising strategy of overcoming defects of bioprosthetic heart valves.

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The zwitterionic hydrogel with VEGF is utilized to improve anti-calcification and re-endothelialization properties of heart valves.

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The hybrid heart valves with a VEGF-loaded zwitterionic hydrogel coating exhibits excellent biocompatibility.

Long-term Outcomes of Transcatheter Aortic Valve Replacement With the Lotus Valve vs CoreValve/EvolutR: A Secondary Analysis of the REPRISE III Randomized Clinical Trial

IMPORTANCE

Long-term follow-up after transcatheter aortic valve replacement (TAVR) is of interest given that longitudinal data on mortality and durability of transcatheter heart valves are limited. The REPRISE III (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System-Randomized Clinical Evaluation) randomized clinical trial compared the mechanically expanded Lotus valve with the self-expanding CoreValve/EvolutR TAVR platforms.

OBJECTIVE

To describe the final 5-year outcomes of the REPRISE III trial.

DESIGN, SETTING, AND PARTICIPANTS

This prespecified secondary analysis assessed the final 5-year clinical, functional, and echocardiographic outcomes of 912 patients from the REPRISE III trial, which was conducted at 55 centers in North America, Europe, and Australia between September 22, 2014, and December 24, 2015. Patients had high risk for aortic stenosis or severe or symptomatic aortic stenosis. Data were analyzed from September 22, 2014, to May 21, 2021.

INTERVENTION

Lotus valve or CoreValve/EvolutR TAVR platforms.

MAIN OUTCOMES AND MEASURES

Valve Academic Research Consortium-2 end points, hemodynamic measures, functional status, and health status were examined through the 5-year follow-up.

RESULTS

A total of 912 patients (mean [SD] age, 82.8 [7.3] years; 463 women [50.8%]) were randomized to either the Lotus valve group (n = 607) or CoreValve/EvolutR group (n = 305), with a baseline Society of Thoracic Surgeons risk score of 6.8%. Clinical follow-up data from the REPRISE III trial were available for 581 patients (95.7%) in the Lotus valve group and 285 patients (93.4%) in the CoreValve/EvolutR group. At 5 years, the cumulative event rate for all-cause mortality was 50.9% in the Lotus valve group vs 52.8% in the CoreValve/EvolutR group (P = .59). Disabling stroke was less frequent with the Lotus valve vs CoreValve/EvolutR (cumulative event rates, 8.3% vs 12.2%; P = .04), whereas the cumulative event rates for overall stroke were similar in both groups (14.1% vs 15.3%; P = .38). Insertion of a new permanent pacemaker (38.9% vs 27.3%; P < .001) and detection of prosthetic aortic valve thrombosis (5.8% vs 1.8%; P = .007) were more common in the Lotus valve group than in the CoreValve/EvolutR group. A smaller proportion of patients who received the Lotus valve experienced valve malpositioning (0% vs 2.6%; P < .001) and required the use of a second valve (1.0% vs 3.8%; P < .001) during the procedure compared with those who received the CoreValve/EvolutR. Compared with the Lotus valve group, the CoreValve/EvolutR group had a significantly lower mean (SD) aortic gradient (7.8 [4.2] mm Hg vs 12.6 [6.7] mm Hg; P < .001) and larger valve areas (1.57 [0.56] cm2 vs 1.42 [0.42] cm2; P = .10). After 5 years, the proportion of patients with moderate or greater paravalvular leak was not significantly higher with the CoreValve/EvolutR than with the Lotus valve (1.9% vs 0%; P = .31); however, the proportion of patients with mild paravalvular leak was higher in the CoreValve/EvolutR group compared with the Lotus valve group (23.1% vs 7.8%; P = .006). Long-term, similar improvements in New York Heart Association class and Kansas City Cardiomyopathy Questionnaire score were observed in both groups.

CONCLUSIONS AND RELEVANCE

The REPRISE III trial found that, at 5 years, the clinical outcomes of the Lotus valve were comparable to those of the CoreValve/EvolutR and that the Lotus valve was safe and effective.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02202434.